check out Robert Browning's poem "The Pied Piper of Hamlin" which mentions more rats than you can shake a stick at!

Aah, what memories! I had a stand-up argument with my fifth form English teacher about this poem - she insisted first that Transylvania was somewhere in North America, then North Africa, then that Romania was an SSR, part of the USSR, first she said de jure, then de facto. This at a time when Romania was a maverick among Eastern Bloc nations. That, together with the great difficulty I had, even then at the height of my love affair with the German language, wrapping my tongue around Hameln, and my identifying with the lame little boy, mean that this opus is indelibly inscribed on what is often mistaken for my mind.